To assure that the M.I.T. Mass Spectrometry Facility remains in the forefront of the field the area of research will be expanded to large polar molecules (up to l0,000 daltons and possibly beyond). Methods for the ionization of such molecules will be improved. Major emphasis will be on "soft" ionization techniques such as field desorption, fast atom bombardment and direct chemical ionization applied to large, polar molecules of biological interest. Laser-induced fragmentation will be investigated as a means for deriving more structural information. Proteins, oligopeptides, nucleotides, membrane structure, sphingo lipids, drug metabolites are major areas of interest. This methodology will be made available to the biomedical community through collaboration or as a service.